Can't get subtitles working.

[msivers]

Can't seem to get subtitles working with SimpleExoPlayer (ExoPlayerXamarin 2.5.1.2).

Using the following urls:
http://clips.vorwaerts-gmbh.de/big_buck_bunny.mp4
http://html5doctor.com/demos/webvtt/subtitles.vtt

Full activity code sample:

[Activity(Label = "VideoPlayerActivity")]
public class VideoPlayerActivity : Activity
{
	private string videoUrl;
	private string captionUrl;
	private SimpleExoPlayerView videoPlayerView;
	private SimpleExoPlayer videoPlayer;

	protected override void OnCreate(Bundle savedInstanceState)
	{
		base.OnCreate(savedInstanceState);

		SetContentView(Resource.Layout.VideoPlayerLayout);

		videoPlayerView = FindViewById<SimpleExoPlayerView>(Resource.Id.VideoPlayerView);

		videoUrl = Intent.GetStringExtra("VideoUrl");
		captionUrl = Intent.GetStringExtra("CaptionUrl");

		LoadVideo(videoUrl, captionUrl);
	}

	public void LoadVideo(string videoUrl, string closedCaptionUrl = null)
	{
		var videoUri = (!string.IsNullOrWhiteSpace(videoUrl)) ? Android.Net.Uri.Parse(videoUrl) : null;
		var captionUri = (!string.IsNullOrWhiteSpace(closedCaptionUrl)) ? Android.Net.Uri.Parse(videoUrl) : null;

		Handler mainHandler = new Handler();
		var bandwidthMeter = new DefaultBandwidthMeter();
		var videoTrackSelectionFactory = new AdaptiveTrackSelection.Factory(bandwidthMeter);
		TrackSelector trackSelector = new DefaultTrackSelector(videoTrackSelectionFactory);

		videoPlayer = ExoPlayerFactory.NewSimpleInstance(this, trackSelector);

		var dataSourceFactory = new DefaultDataSourceFactory(this, Util.GetUserAgent(this, "VideoPlayer"), bandwidthMeter);
		var extractorsFactory = new DefaultExtractorsFactory();
		var videoSource = new ExtractorMediaSource(videoUri, dataSourceFactory, extractorsFactory, null, null);

		if (captionUri != null)
		{
			var subtitleFormat = Format.CreateTextSampleFormat(null, MimeTypes.TextVtt, C.SelectionFlagDefault, null);
			var subtitleSource = new SingleSampleMediaSource(captionUri, dataSourceFactory, subtitleFormat, C.TimeUnset);

			MergingMediaSource mergedSource = new MergingMediaSource(videoSource, subtitleSource);

			videoPlayer.Prepare(mergedSource);
		}
		else
		{
			videoPlayer.Prepare(videoSource);
		}

		videoPlayer.PlayWhenReady = true;
		videoPlayerView.Player = videoPlayer;
	}
}

Only first frame of video is shown - can't play video. If I remove the subtitleSource parameter from the MergingMediaSource constructor then the video plays fine so there seems to be something wrong with the creation of the SingleSampleMediaSource instance. I've tried lots of different variations of parameters for CreateTextSampleFormat but nothing has worked so far.

Help or guidance would be greatly appreciated.

[martijn00]

Is this related to google/ExoPlayer#3228? If so it would be fixed after updating to 2.5.2

[martijn00]

The update is out on nuget. Can you let me know if that helps?

[msivers]

Hi Martjin, I've tried with version 2.5.3 and still doesn't work. Can you replicate the problem as I think this is general issue of using mp4 and vtt files?

[devmartinez0]

@msivers If you are using a VTT subtitle file you need to enable Close Captions in your Device's Settings > Accessibility > Captions (the languaje of the captions must be the same as the subtitle file).

[martijn00]

Can you try 2.7.2?